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2018 Niner

SIR 9 5-STAR

A 27.5″ steel frame hardtail trail bike with ultra high-end components.
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Manufacturer Price

$5,950
FrameSteel
SuspensionHardtail, 120mm
ForkFox Factory Float 34
Wheels27.5″ Carbon
Drivetrain1 × 12
GroupsetX01, X01 Eagle
BrakesSRAM Guide RSC Hydraulic Disc
SeatpostDropper
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Insights
Ride Feel

Based on frame geometry and build specs.

Terrain
easyextreme
Handling
nimblestable
SIR 9 5-STAR
Other Trail bikes
Gearing

A bike with lower gearing will be easier to ride up steep hills, while a higher top end means it will pedal faster down hills.

Lowest gear

(climbing)

28 mph

SIR 9 5-STAR

26 mph

Similar Bikes

Highest gear

(descending)

Sizing
SM

5'2" – 5'8"

MD

5'6" – 5'11"

LG

5'10" – 6'3"

XL

6'1" – 6'7"

🐐 Estimated

Rider Fit Notes

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Reviews

Summary

The Niner SIR 9 is a versatile cross-country bike praised for its durable Reynolds 853 steel frame, modern geometry, and ample bikepacking features. It offers a comfortable and stable ride, with handling that inspires confidence both uphill and downhill. The bike's compatibility with multiple wheel sizes and drivetrain options adds to its appeal for a wide range of riders.

Pros
  • Durable Reynolds 853 steel frame

  • Modern geometry for confident handling

  • Ample bikepacking features and mounting options

  • Compatible with multiple wheel sizes and drivetrains

  • Comfortable and stable ride quality

Cons
  • Initial feel of 27.5+ wheels as heavy and slow to accelerate

  • Requires adjustment period for those used to super-light 29er race bikes

  • 73mm PF30 BB shell requires adaptors for BSA type BBs

Key Quotes
A lively, modern geometry suited to challenging trails, both up and down.
BIKEPACKING.com
It’s a solid, well-built machine that really does make you feel like you can head out for days.
Mountain Flyer logoMountain Flyer
Niner’s new shred-ready hardtail can accommodate 29er or 27.5+ wheels.
MTBR logoMTBR

Feedback?

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Mountain Flyer
Tested: Niner SIR 9

Oct 2018

I have to admit — I am somewhat of a crusty old dude and sometimes resist change until it has been thoroughly tested by others. This being the case, I was a bit doubtful when I first climbed on the Niner SIR 9, a steel hardtail that can run 27.5-plus or 29-inch wheels. The 27.5x 2.80 tires seemed like overkill compared to my super-light 29er race bike, and the thought of riding a bike that wasn’t fully suspended had me questioning my sanity.

Read Review

BIKEPACKING.com
Niner SIR 9 Review, Tested on the Colorado Trail

Oct 2017 · Cass Gilbert

Like steel hardtails? We test the Niner SIR 9, boasting a modern, slack geometry, room for 27.5+ tires, and a host of bikepacking-friendly details.

Lows
  • Although its gear range is excellent, SRAM XO1 Eagle feels built for racing rather than bikepacking. It’s fiddly to set up and sensitive to cable stretch.

  • Press fit bottom bracket requires specialist tools that may be hard to find in the backcountry.

  • While an eccentric insert is available, none of the standard builds include it.

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BIKE Magazine
Niner Updates the SIR 9

Jun 2017

The Niner SIR 9 gets the longer, lower, slacker treatment

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MTBR
Niner SIR 9 trail bike launched

Jun 2017 · Mtbr

News out of the Niner camp today. The Colorado-based bike maker has re-released its original steel classic, the SIR 9, in a redesigned, ready for anything form. - Mtbr.com

Read Review

Geometry
Specs
Build
Frame

SIR 9 - SLATE BLUE/ORANGE

BB StandardPF30, Press Fit

Tire Clearance2.4"

Fork

FOX 34 FLOAT FACTORY FIT4, 3 POSITION W/ ADJ, KASHIMA COAT, 120MM, 110X15MM

Travel120mm

Spring TypeAir

Shock

N/A

Bottom Bracket

SRAM%20PF30

Headset

NINER INTERNAL ZS SHIS DESCRIPTION ZS44/28.6|ZS56/40

Stem

RACE FACE TURBINE BASIC 50MM, 35MM CLAMP

Handlebar

RACE FACE SIXC 820MM WIDE, 20MM RISE, 35MM CLAMP

Saddle

NINER CUSTOM TR WITH CRN-TI RAILS, PRINTED NINER GRAPHIC

Seatpost

KS LEV INTEGRA

TypeDropper

Pedals

N/A

Grips

NINER GRRRIPS L/O FLANGED

Groupset
Rear Derailleur

SRAM Eagle X01, 12-speed

Crank

SRAM X1 EAGLE CARBON GXP 32T CNC RING

Shifters

SRAM X01 EAGLE 12SP

Cassette

SRAM EAGLE XG 1295, 10-50T

Chain

SRAM X01 EAGLE 12SP

Chain Guide

N/A

Brakes

SRAM GUIDE RSC

TypeSRAM Guide RSC Hydraulic Disc

Brake Levers

SRAM GUIDE RSC

Wheels
Rims

Niner Carbon XC

Spokes

32 count front and rear

Front Hub

DT Swiss 350, 15mm x 110mm, 12mm x 148mm, XD Driver

Rear Hub

DT Swiss 350, 15mm x 110mm, 12mm x 148mm, XD Driver

Tires

29" MAXXIS ARDENT DC/EXO/TR 2.4

Rider Notes
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First added March 30

Last updated April 14

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